Improvement in saws



JosEPH H-.SMITHIA-ND ELIYJiAH e. PECKHAM, or ToLED'aoHid llftetiters.Patent No, 95,052, dated September 21, 1869.

IMPROVEMENT IN SAWS.

The Schedule referred toy in these Letters Patent and making .part ofthe same.

To all whom it may concern: -r

Be it known that we, JOSEPH H. SMITH and ELI- JAH G. PEGKHAM, of Toledo,in the countyl of Lucas,`

`and State of Ohio, have invented a new and useful Improvement onSaw-Teeth; and' we do hereby de# clare that the following i s a full,clear, and exact description thereof', reference beinghad to theaccompanying drawings, making part of this specication, in which,- t YFigure 1,` plate 1, is a side view of a portion of a saw-blade havingthe improed saw-teeth formed on it.

Figure 2 is an end view of iig. 1.

Figure 3 is an edge view of the saw-teeth;

Figure 4, plate 2, is `a diagram illustrating an old form of saw-teeth,in full lines, vand showing, by the aid of dotted lines, the manner-ofproducing our improved teeth.

Similar letters of reference indicate 'corresponding parts in theseveral gures.

lhis invention relates toan improvement on the l construction of teethforcross-cut saws and consists in alternate pairs ofv straightcutting-teeth, whichare separated individually by a narrow straightslit, and which terminate'at their ends in double-bevelledcutting-edges, in combination with an intermediate single raker or'clearingftooth, whichv has obtuse angles on' opposite edges, and acentral acute clearing-point, as willl be hereinafter explained.

We are aware that cross-cut saws have been made hefore'our inventionwith single clearing-teeth arranged between pairs of cutting set-teeth,the latter teeth being separated individually by narrow slits extendinginto the saw-blade only as far as the bases of the clearers,'and we donot claim, broadly, such an arrangement of set-teeth and clear-ers asour invention.

The followingdescription of our improved saw-teeth `will enable othersskilled in. the art to understand their construction and operation.

In the accompanying. drawings, figs. l and 3, we have represented aportion-of a saw-blade having formed upon one edge three pairs ofcutting setf teeth and three intermediate singlel rak'ers orclearing-teeth.

,` The set-teeth cnt `downthe sides ci' the kerf, while ,the clearersremove the ridge left between the two parallel cuts made by theset-teeth.

In the constr'uction of this class of cross-cut saws, it is important-First, -to lprovide free clearance for the dust, to preventitaccumulating between the teeth and about their cutting-edges;

Second, to prevent gumming, by cutting narrow slits into the blade atthose points where'the gumkerf will be cut before the clearers scrape orcut Ofi the ridge;

Fourth, 'to employ clearers which will not collect the dust, norinterfere with the` cutting of the stteeth;

Fifth, to obtain as much space as possible betweenv a given number ofteeth in a given length of' blade, without weakening the teeth; and

Sixth, to so shape the teeth that they can be sharpened and kept sharpwith the least amount of labor and removal of metal.

.a a, represent the cutting or set-teeth, which are'A spacedin pairs,with a narrow parallel slit, d, between the teeth of each pair.

These teeth a a. are straight, that is to say, their edges are parallel,and `terminate in idouble-bevelled or angular cutting-points, which aresharpened and set as shown in the drawings. l,

By making the edges of the teeth a (t parallel or perpendicular to thelength of the saw-blade A, and producing the cutting-edges ofylievelling each tooth equally on each edge o, triangular cutting-pointsare formed, which can be regularly sharpened.

Between every two pairs of cutting-teeth a a, and equidistaut from thecentres of the slits d, is a tooth, b, on each side of which a space, e,is formed, which is carried further into the saw-blade than the slits d.

The spaces e e terminate, along their edges next the back ofthe'saW-blade, in semicircles,which, as they do .not present angles,will prevent an laccumulation of sawdust in said spaces. t a Eachclearing-tooth b is tapered from Aits base to the `points i i, and fromthese points or to the acute angle s, the edges j' f are abruptlybevelled, so as to .leave obtuse angles at the junction of the edges f(1, on each sidc ofthe tooth.

The teeth b, thus constructed, will cut or vclear in the forward well asbackward movements of the saw, and they will not clog with sawdust, likethedouble-edge clearers hitherto used in combination with pairs ofset-teeth.

In sharpening the clearers b, the file is applied upon the shortbevelled edgesV f, and a very small amount' ofthe metal is required tobe removed to effect Athey sharpening, while, at the same time, thetooth is not black lines show a pair of set-teeth separated by a slit,

which leaves one Yedge of each set-tooth perpendicular to the. length ofthe saw-blade, while the opposite edge of each set-tooth is hevelledfrom its cutting-point to its base.

The olearers, which are between the pairs of setteeth, are of a, V oracute angular shape. In filing these teeth, gunimiug cannot beprevented, and n eomparatively large amount of metall must be removed bythe le to keep the teeth sharp. i

By removing the metal as indicated by the-dotted lines, we formsetFteeth with parallel edges, we round out and deepen the spaces on theopposite sides of the elenrers, and we reduce the width oftlie'elearers, so that the most inexperienced 'hand can Sharpen theteeth without gumming.

As a greater amount of space is required between the elearers andset-teeth than is required between each pair of set-teeth to preventclogging, it will be seen tba-t we do not cut the slits d `into theblade as ir as the spaces e extend, but leave such an amount of metal etthe bases of the set-teeth as will afford them all the strengthrequired.

Having described our invention, v

What We claim as new, and desire te secure by Letters Patent, is*- j Thesnw-bmle, which combines in its construction pairs of teeth, separatedbelow their cutting or sharpening-bevel, and an intermediate singleclearingtocth, which has nn angle, t, en each of its sides,substantinlly as described.

JOSEPH H. SMITH. ELIJAH G. PECKHAM.

Witnesses:

AVERY S. HILL, JAMES BADDEL-r.

